In conventional diagnosis of lung cancer, images of a patient's lungs are first picked up using X-rays or CT (computed tomography), and primary diagnosis is conducted. Based on the images picked up, the presence or absence of a nodule in the lung field is checked. When the presence of a nodule is confirmed, secondary diagnosis is conducted by a method in which a biopsy device is inserted into the bronchus through a bronchoscopy and tissue in the living body is sampled by the biopsy device. Then, vital histological diagnosis is conducted in which the sampled tissue is observed.
A conventional biopsy system for performing the above-mentioned biopsy is disclosed, for example, in Japanese Patent Laid-open No. 2003-164455. This application publication describes a technology using a system including an ultrasonic probe which acquires an ultrasonic image of the inside of a living body, and a puncture needle which protrudes from the ultrasonic probe and by which tissue is sampled.
In the technology described in Japanese Patent Laid-open No. 2003-164455, the ultrasonic probe is first inserted into the living body, and an image of the bioptic target part to be bioptically examined is acquired. Then, while observing the image picked up by the ultrasonic probe, the puncture needle is made to puncture the bioptic target part, thereby sampling the tissue.
According to the technology disclosed in Japanese Patent Laid-open No. 2003-164455, however, the ultrasonic probe constituting a tomographic image pick-up device and the puncture needle as a biopsy device are inserted into the living body in the mutually overlaid state. In addition, the biopsy device is thick, in order to sample the tissue in an amount sufficient for biopsy. As a result, in the technology disclosed in the above-mentioned application publication, the member inserted into the living body together with the ultrasonic probe is large in diameter. This leads to a problem, for example, in that the biopsy device and the ultrasonic probe cannot be inserted into a peripheral region where the nodule is found of the bronchus in the vicinity of the alveoli.
In addition, when the biopsy device to be inserted together with the ultrasonic probe constituting the tomographic image pick-up device is reduced in diameter, the amount of the tissue which can be sampled would be decreased.
Furthermore, there has also been proposed a biopsy method as follows. First, only an ultrasonic probe is inserted into a living body to confirm the position of the bioptic target part, followed by pulling the ultrasonic probe out of the living body. Thereafter, a biopsy device is inserted to the position where the bioptic target part is confirmed by the ultrasonic probe, and tissue is sampled. According to this biopsy method, the biopsy device can be inserted to a peripheral region in a living body.
However, the ultrasonic probe has been withdrawn out of the living body when the tissue is sampled by inserting the biopsy device. This has led to the problem that it cannot be checked whether the biopsy device has assuredly reached the bioptic target part.